The industrial-scale production of hard carbon anodes remains a critical challenge yet to be fully overcome. The bottleneck for sodium-ion battery industrialization is now intensely focused on hard carbon anodes. Since 2026, battery manufacturers like CATL and Gotion High-tech have frequently signaled the imminent mass production of sodium-ion batteries. On April 21, CATL announced during its Super Tech Day that its sodium-ion batteries would achieve large-scale production by the end of 2026. Six days later, CATL signed a three-year cooperation order with Hyposi for 60 GWh of sodium-ion batteries for energy storage. CATL also disclosed that it had overcome four major industry challenges in sodium-ion battery mass production: extreme moisture control, gas generation from hard carbon, aluminum foil bonding bottlenecks, and the scaled production of self-generating anodes.

This order has brought hard carbon anodes into the spotlight. Unlike lithium-ion batteries, which predominantly use graphite anodes, sodium ions have a larger radius and cannot stably intercalate into graphite layers. Consequently, hard carbon has become the mainstream anode material for current sodium-ion batteries. However, producing hard carbon is not as simple as carbonizing agricultural and forestry waste at high temperatures. Factors including precursor source, raw material yield, ash content and impurities, initial Coulombic efficiency, compaction density, gas generation, moisture control, and batch consistency collectively determine whether sodium-ion batteries can truly enter the phase of large-scale delivery.

Around the CIBF 2026 exhibition, hard carbon anode companies intensively released new updates. Shengquan Group disclosed that it had established a 10,000-ton annual production line for hard carbon anodes, with its products validated for multiple applications such as energy storage batteries and 3C consumer batteries, and that it had entered the supply chain of leading cell manufacturers. Kbc Corporation launched two new ultra-high purity hard carbon products, KBHC300 and KBHC330, with impurity content controlled below 0.1%. Jingjiu Company, under Shaanxi Coal Chemical Industry Technology Research Institute, also announced that its coal-based hard carbon anode products for sodium-ion batteries had begun mass production and delivery to leading industry players.

These developments point to a common shift: competition in hard carbon anodes is evolving from early-stage reliance on biomass routes like coconut shells to the parallel validation of multiple pathways, including straw, resin-based, bamboo-based, coal-based, and plastic-based precursors. The low-cost narrative of sodium-ion batteries is being recalibrated by hard carbon realities.

Coconut shells were once repeatedly cited as an ideal raw material in the early development of hard carbon anodes. Their advantages include a relatively stable structure and lower ash content; after carbonization and activation, they can potentially yield pore structures and disordered carbon layers suitable for sodium-ion storage. However, as sodium-ion batteries transition from sample validation to GWh-scale delivery, the shortcomings of the coconut shell route have become apparent: the raw material is geographically constrained, with a limited supply radius. Processes like drying, screening, impurity removal, and ensuring batch stability require additional costs. From a scale perspective, fulfilling a 60 GWh order relying solely on coconut shell-based hard carbon would require approximately 240,000 tons of dry coconut shells annually, equivalent to over 500,000 tons of raw coconuts. Global coconut supply growth cannot keep pace with such demand.

Some companies have directly addressed this issue. Shengquan Group's related materials mention that its reconstituted resin-based porous carbon uses by-products from biomass refining, aiming to solve the industry challenges of high raw material volatility and poor batch stability associated with coconut shell-based materials. In its 2025 annual report, Zhejiang Tuna Environmental Science & Technology Co., Ltd. explicitly stated that it chose coal-based raw materials for its hard carbon anodes because coal-based materials are common, have low transportation costs, are not subject to seasonal or geographical restrictions, and offer higher yields than biomass routes like coconut shells and straw.

This indicates that coconut shell-based hard carbon has not been technically invalidated, but its stability as a large-scale industrial raw material is being reassessed by companies. For sodium-ion batteries, abundant and inexpensive sodium resources do not automatically translate into cheap batteries. If a stable, low-cost, and replicable raw material system for hard carbon anodes cannot be established, the cost gap between sodium-ion batteries and lithium iron phosphate (LFP) batteries will be difficult to widen significantly.

Among the various alternative routes, Shengquan Group is one of the companies with relatively clear publicly disclosed progress. Leveraging its integrated biomass refining industrial chain, Shengquan has built a 10,000-ton hard carbon anode production line. Its uniqueness lies in not being a traditional graphite anode leader but entering the hard carbon field from biomass refining, phenolic resin, and chemical new material systems. Compared to simply collecting dispersed raw materials like coconut shells or nut shells, its approach emphasizes converting biomass resources into controllable precursors, which then enter the battery material system through carbonization, reconstitution, pore creation, and surface modification.

The industrial significance of this route is that the competitive boundaries for hard carbon anodes are expanding. Historically, the anode industry primarily revolved around graphitization, needle coke, petroleum coke, and integrated artificial graphite production. Sodium-ion battery hard carbon anodes are now bringing biomass refining, resin chemical companies, porous carbon specialists, and coal chemical enterprises to the forefront. Whoever can transform low-value, dispersed, and volatile carbon sources into battery-grade materials may secure a ticket to sodium-ion battery industrialization.

Coal-based hard carbon is becoming another intensively validated route. In its 2025 annual report, Zhejiang Tuna Environmental disclosed that it uses coal-based raw materials for its hard carbon anodes. The company's reasoning is straightforward: coal-based materials are common, have low transportation costs, are not limited by season or region, and offer higher yields than biomass routes like coconut shells and straw. By the end of the reporting period, the company had completed the construction of a thousand-ton-scale layered oxide cathode material production line and a pilot production line for coal-based anodes. Samples are being sent to downstream customers for small-batch testing and pre-production trials. In April this year, it was reported that Jingjiu Company, under Shaanxi Coal Chemical Industry Technology Research Institute, had begun mass production and delivery of its HC260 and HC300 coal-based hard carbon anode products to leading industry enterprises, with sample testing covering major manufacturers like CATL and BYD.

The advantages of the coal-based route are not difficult to understand. China has abundant coal resources, a mature supply chain, and stronger raw material organization capabilities compared to dispersed biomass. If coal-based hard carbon can meet cell manufacturers' requirements for capacity, initial efficiency, impurities, rate capability, and cycle life, it has the potential to become a significant supplement for the low-cost industrialization of sodium-ion battery anodes.

However, the coal-based route is not inherently superior. As a battery material, hard carbon must ultimately pass electrochemical performance tests. The structural regulation of coal-based precursors, control of ash and metallic impurities, surface functional group treatment, initial cycle efficiency, and long-term cycle stability all directly impact cell performance. Whether coal-based hard carbon can progress from sample testing to volume supply depends on the certification results and continuous delivery performance from leading cell manufacturers.

Regarding the bamboo-based route, technological iterations continue to address inherent defects like high ash content and poor consistency. In May 2026, Wanrun New Energy applied for a patent to optimize bamboo powder-based hard carbon through oxidative pretreatment and co-doping technology. On the industrial front, Ningna Technology, located in Ningyuan, Hunan, has built China's first industrial production line for bamboo-based hard carbon anode materials, which has entered trial production. At CIBF 2026, Kbc Corporation launched its KBHC series of ultra-high purity hard carbon anode products for sodium-ion batteries, KBHC300 and KBHC330. Public information indicates that both products have impurity content controlled below 0.1% and emphasize cycle life, initial efficiency, and rate performance.

The challenges for sodium-ion battery hard carbon anodes extend beyond raw material costs to include impurities, side reactions, and gas generation control. The complex pore structure of hard carbon, along with its specific surface area, surface functional groups, and residual impurities, can affect electrolyte decomposition, SEI film formation, and initial Coulombic efficiency. For energy storage applications, where individual cell capacities are larger and system lifespan requirements are longer, minor fluctuations at the material level can be magnified into issues of consistency and longevity. Therefore, during CIBF, companies no longer focused solely on "what raw material is used to make hard carbon" but began discussing "to what level impurities can be reduced," "what initial efficiency can be achieved," and "whether rate capability and cycle life can be balanced." This marks a sign of hard carbon transitioning from a material story to cell validation.

The industrialization of hard carbon will ultimately be defined by battery manufacturers. Among the four major mass production challenges disclosed by CATL during its Super Tech Day, "hard carbon gas generation" and "extreme moisture control" directly point to engineering bottlenecks in anode materials. Following the signing of the 60 GWh energy storage sodium-ion battery cooperation with Hyposi, it was further reported that CATL is enhancing the energy density of its sodium-ion batteries through morphology control and surface modification. It is also addressing mass production issues like foaming in hard carbon production lines and moisture control through technologies such as pore size regulation, surface molecular water locking, and adaptive dynamic formation.

This indicates that hard carbon is no longer a problem that material companies can solve by merely providing powder. Once incorporated into cells, it must undergo manufacturing processes including slurry mixing, coating, calendering, drying, electrolyte filling, and formation. The pore size distribution, surface state, moisture content, and impurity levels of hard carbon all impact gas generation, initial efficiency, consistency, and yield. For battery manufacturers like CATL, the hard carbon supply chain must be integrated into a system matching materials, electrolyte, formation protocols, and the manufacturing environment. Only those who can enter the supply chain of leading cell manufacturers have truly completed the leap from material specifications to mass production specifications.

This is also why the progress announced by companies like Shengquan Group, Kbc Corporation, Shaanxi Coal Jingjiu, and Zhejiang Tuna Environmental needs to be re-examined in the context of CATL's 60 GWh order. The larger the sodium-ion battery order, the more the validation criteria for hard carbon anodes shift from mere laboratory capacity to continuous batch performance, cost, gas generation, initial efficiency, and consistency.